AB1034 NO DIFFERENCES IN HEPATITIS B ANTIBODY POSITIVITY IN CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS ON BIOLOGICAL THERAPY

Abstract

Background Biologic disease-modifying antirheumatic drugs (DMARDs) are frequently used in the treatment of juvenile idiopathic arthritis (JIA) resistant to nonbiologic DMARDs recently. There is a concern for their reducing the effectiveness of vaccines due to immunosuppresive effects. Objectives To evaluate hepatitis B antibody (anti-HBs) positivity and antibody titers between JIA patients on biologic DMARDs therapy and healthy conrols. Methods Anti-HBs antibody positivity and titers were compared between 88 patients with JIA on biologic DMARDs therapy followed in our clinic and 91 healthy controls aged 2-19 years. All participants were vaccinated according to the routine vaccination schedule in our country. Results Eighty-eight JIA patients included and fifty five (62,5%) patients were female. The median age of patients was 13,31 (4,07-18,08) years. The JIA subtypes were systemic JIA (10,2%), oligoarticular JIA (33%), poliarticular JIA (25%), entesitis related arthritis (26,1%), psoriatic JIA (3,4%), and undifferantiated JIA (2,3%). The median duration of biologic DMARDs was 31,995 (1,33-115) months. 54 patients were treated only with one anti-TNF (34 etanercept, 17 adalimumab), 16 patients were treated more than one TNF-alfa inhibitor. 18 patients were treated with more than one different group biologic DMARDs, and 7 of them had more than two biologic DMARD due to disease activity. Anti-HBs positivity was 67% in the JIA group and 54,9% in the control group, and no significant difference detected between the two groups (p=0,097). The anti-HBs titer was 12,95 (min-max: 2-1000) in the controls and 22,44 (2-1000) in the biological DMARDs. Conclusion Patients with JIA on biologic DMARDs had not lower anti-HBs positivity than healthy controls in our study. Further studies are required to understand the effects of biologic DMARDs on protective anti-HBs antibody levels. Disclosure of Interests None declared